图像过滤器太慢

Question

我需要对此代码段进行特定的重写才能更快地运行它。 我几乎不能从这段代码中获得5fps，我需要30fps才能顺利运行它。 需要有关如何重写它以更快运行的帮助..

我在媒体播放器上使用它作为过滤器来增强媒体中的不良帧，所以在更高的分辨率上看起来好一点..

    public static Bitmap MedianFilter(this Bitmap sourceBitmap, int matrixSize, int bias = 0, bool grayscale = false)
    {
        BitmapData sourceData = sourceBitmap.LockBits(new Rectangle(0, 0, sourceBitmap.Width, sourceBitmap.Height), ImageLockMode.ReadOnly, PixelFormat.Format32bppArgb);

        byte[] pixelBuffer = new byte[sourceData.Stride * sourceData.Height];

        byte[] resultBuffer = new byte[sourceData.Stride * sourceData.Height];

        Marshal.Copy(sourceData.Scan0, pixelBuffer, 0, pixelBuffer.Length);

        sourceBitmap.UnlockBits(sourceData);

        if (grayscale == true)
        {
            float rgb = 0;

            for (int k = 0; k < pixelBuffer.Length; k += 4)
            {
                rgb = pixelBuffer[k] * 0.11f;
                rgb += pixelBuffer[k + 1] * 0.59f;
                rgb += pixelBuffer[k + 2] * 0.3f;


                pixelBuffer[k] = (byte)rgb;
                pixelBuffer[k + 1] = pixelBuffer[k];
                pixelBuffer[k + 2] = pixelBuffer[k];
                pixelBuffer[k + 3] = 255;
            }
        }

        int filterOffset = (matrixSize - 1) / 2;
        int calcOffset = 0;

        int byteOffset = 0;

        List<int> neighbourPixels = new List<int>();
        byte[] middlePixel;

        for (int offsetY = filterOffset; offsetY < sourceBitmap.Height - filterOffset; offsetY++)
        {
            for (int offsetX = filterOffset; offsetX < sourceBitmap.Width - filterOffset; offsetX++)
            {
                byteOffset = offsetY * sourceData.Stride + offsetX * 4;

                neighbourPixels.Clear();

                for (int filterY = -filterOffset; filterY <= filterOffset; filterY++)
                {
                    for (int filterX = -filterOffset; filterX <= filterOffset; filterX++)
                    {

                        calcOffset = byteOffset + (filterX * 4) + (filterY * sourceData.Stride);

                        neighbourPixels.Add(BitConverter.ToInt32(pixelBuffer, calcOffset));
                    }
                }

                neighbourPixels.Sort();

                middlePixel = BitConverter.GetBytes(neighbourPixels[filterOffset]);

                resultBuffer[byteOffset] = middlePixel[0];
                resultBuffer[byteOffset + 1] = middlePixel[1];
                resultBuffer[byteOffset + 2] = middlePixel[2];
                resultBuffer[byteOffset + 3] = middlePixel[3];
            }
        }

        Bitmap resultBitmap = new Bitmap(sourceBitmap.Width, sourceBitmap.Height);

        BitmapData resultData = resultBitmap.LockBits(new Rectangle(0, 0, resultBitmap.Width, resultBitmap.Height), ImageLockMode.WriteOnly, PixelFormat.Format32bppArgb);

        Marshal.Copy(resultBuffer, 0, resultData.Scan0, resultBuffer.Length);

        resultBitmap.UnlockBits(resultData);

        return resultBitmap;
    }